Assuming that in Harappan era, rocks, stones and pebbles were used for money. The following used to be the currency valuations: 1 rock = 7 stones, 1 stone = 7 pebbles. If a person used 6 rocks to purchase a cave that cost 5 rocks, 2 stones and 3 pebbles, then how much would the change be?

• A. 4 stones, 4 pebbles
• B. 5 stones, 4 pebbles
• C. 1 rock, 5 stones, 4 pebbles
• D. 5 stones, 5 pebbles